Zigzag sewing machines



May 6, 1958 A. F. D'AMIco ZIGZAG SEWING MACHINES 4 Sheets-Sheet 1 Filed May 27.

A IN1/nvm. Anthony F DAm/'co w/T/vEss May 6, 1958 A. F.D'AMlco zmzAG SEWING MACHINES Filed May 27.

4 Sheets-Sheet 2 50 7e so 8l 63. 66

nvVENToR,` Anfhony F D'Amico ATTORNEY May 6, 1958 A. F. D'AMICO 7 2,833,233

v ZIGZAG SEWING MACHINES im E I. 'Il

IN V EN TOR.A

Anhon F D'Amico May 6, 1958 A. F. D'AMlco ZIGzAG SEWING MACHINES 4 Sheets-Sheet 4 Filed May 27. 1954 JNVENTOR. Amhony F D'Amico WITNESS 7%@ ZlGZAG SEWENG MACHINES Anthony F. DAmico, South Norwalk, Conn., assigner to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application May 27, 1954, Serial No. 432,637

6 Claims. (Cl. 112--158) This invention relates to improvements in zigzag stitch sewing machines of the laterally vibrating needle type, and has for an object provide such a machine with a novel mechanism including a rotary pattern cam for producing the lateral needle vibrations.

Another object of the invention is to provide in combination with a rotary pattern cam mechanism manually controllable means for altering the pattern of lateral needle vibrations generated by the pattern cam.

A further object of the invention is to provide a novel form of mechanism for translating the rotary motions of the pattern cam into lateral vibratory needle-bar motions.

With the above and other objects in view, the invention. comprises the devices, combinations and arrangements of parts hereinafter described in connection with the accompanying drawings which illustrate a preferred embodiment of the invention from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In the drawings:

Fig. l represents a rear side elevation of a sewing machine containing the present improvements and having its rear cover-plate removed sol that the internal mechanism may be viewed.

Fig. 2 represents, on an enlarged scale, a top plan view, partly in section, of the sewing machine illustrated in Fig. l, which sewing machine has its top cover-plate removed in order that the mechanism may be viewed.

Fig. 3 represents avertical sectional view taken substantially along the line 3-3 of Fig. 2.

Fig. 4 represents a sectional view taken substantially along the line 4--4 of Fig. 3.

Fig. 5 represents, on an enlarged scale, a modified form of that needle-bar control mechanism which is illustrated in Figs. 1 and 4.

Fig. 6 represents a sectional View taken substantially along the line 6 6 of Fig. 5.

Figs. 7, 9 and 1l representjdetailed views of the needle gate vibrating pitman of the type disclosed in Figs. 5 and 6 and diagrammatically illustrating the eifects of the pitman controlling mechanism in causing the needle to vibrate across and from eachY side of the neutral position of non-vibration of the needle.

Figs. 8, l0 and l2 each represents a sectional viewr taken respectively along the line 8-S, 10--10 and 12-12 of the. Figs'. 7, 9 and 11.

Figs. 13 represents a portion of the front side1 of the sewing machine frame and particularly illustrates the one end. portion of the cam follower lever.

The present improvements illustrated in the drawings and herein described are embodied in a zigzag. stitch sew'- ing machine of the type disclosed in United States patent of Bolter, No. 2,297,197, dated September 29, 1942,.

Referring to the drawings, the sewing machine illustrated has a bed-plate 15 affording a work-support from one end of which bed-plate rises a hollow standard 16 of a bracket-arm 17 overhanging the bed-plate and terminating at its freeend in' a head 18.

' nite States Patent C M Patented May 6, 1958 The bracket-arm 17 is open at its upper portion to provide access to the internal mechanism, which opening is designated by the numeral 19 (see Figs. 1 and 2) and is adapted to be closed by means of a cover-plate 20 which is removably :secured in position over the opening 19 by any conventional means.

Rotatably journaled in suitable bearings provided in the bracket-arm 17 is a horizontally disposed main shaft 21 extending lengthwise of the bracket-arm and carrying at one end a driving pulley 22. At its opposite end, the main shaft 21 is connected to drive a yconventional type of needle-thread take-up mechanism, not herein shown, as well as a needle-bar designated by the numeral 23.

The needle-bar 23 carries at its lower end a needle 24 and is journaled for endwise reciprocation in suitable bearings provided in a vibratory frame or gate 25. The frame 25 is pivotally hung in a conventional manner upon a screw stud 26 carried by the upper portion of the head 1S to provide for swinging vmovements of the frame 2S about a pivot axis substantially transverse to the axis of rotation of the main shaft 21.

Cooperating with the needle 24 below the bed-plate 15 in the formation of stitches is the usual loop-taker mechanism which is not illustrated as it forms no part of the present invention. Also located beneath the bedplate 15, but not herein illustrated, is the usual type of work-feeding mechanism.

Extending rearwardly from the lower end of the needle bar frame 25 is an arm 26 to which a pitman 27 is pivotally secured by means of a pivot stud 28. The pitman 27 is disposed within the hollow bracket-arm 17 and it extends lengthwise of said bracket-arm so that its rear end portion may be connected with mechanism which actuates the pitman back and forth lengthwise of itself thereby to impart lateral zigzag movements to the needle-bar frame 25 and its associated needle 24. This mechanism may also be adjusted so as to maintain the needle-bar frame in a xed position thereby to permit the needle 24 to be reciprocated up and down in a fixed vertical path to produce straight stitching.

More specifically, the rear end portion of the pitman 27 is adapted to be connected by way of mechanism, hereinafter described in detail, to a rotary pattern cam 29, the peripheral portion 30 of which may be tracked by a cam follower for the purpose of imparting a predetermined pattern of motion to the pitman 27 to the end that a predetermined pattern of ornamental stitching may be produced by the sewing machine. The rotary pattern cam 29, as will hereinafter be described, may be removed from the machine to the end that other pattern cams may be substituted therefor so that the operator may produce various types of ornamental stitch patterns by mere ly changing the patterns cams.

Referring particularly to Figs. l, 2 and 3, the pattern cam 29 is provided with a central yaperture 31 so that the cam may be mounted upon the distal end portion of a shaft 32 which is suitably mounted in bearing bosses 33 and 34 formed within the bracket-arm 17. The distal end portion of the shaft 32 is provided with a cylindrical collar 3S against which the cam 29 may be placed and locked by means of a thumb nut 36. The

thumb nut 36 may be tightened against the cam 29 due An intermediate portion of the rotary cam shaft 32 has fixed thereon a gear 39 which meshes with the worm gear 40 lixed upon the rotary main shaft 21. Thus, rotation of the main shaft 21 will, through the substantially cylindrical tracking element 66 which is j gears 39 and 40, rotate the cam 29 at a predetermined speed.

Referring particularly to Figs. l, 2 and 3, there is mounted within the bracket-arm 17 and between the sidel walls `thereof an `oscillatoryy shaft 41 which is disposed in parallelism with the'rotary cam shaft 32. One end portion of the rock-shaft 41 extends through the forward wall of the bracket-arm 17 and has fixed thereon by means of a screw 42 a bell-crank lever 43 of which `one arm 44 carries a laterally projecting follower element [45 which is normally biased into engagement against the periphery 30 of the cam 29 by means of a coil spring` 46. As may be best seen from Fig. 2, the

spring 46 has its one end portion secured to a post 47 fixed within the bearing boss `33, while the other end portion of the spring is connected with a post 48 carried by a collar 49 fixed tothe rock-shaft 41 in a conventional manner. The springl 46 will `urge the rockshaft to turn in a direction such that the camfollower 45 will faithfully track .the peripheral portion of the cam 29 to the end that theedoek-shaft 41 will be oscillated back and forth in conformity with the pattern of the cam.

As may be observed `from Figs. l, 2 and 13, an arm 50 of the bell-crank lever 43 is disposed directly beneath aboss 51 provided at the forward side of the bracketarm 17, which bosshas threaded therein `a screw 51 whose lower portion is disposed directly above the free end of the arm 50 so as to function as an adjustable stop for arresting the downward movement vof the arm 44 andthe cam follower 45 kin the event that the cam 29` is removed from the machine. A nut 52 4cooperates with` the screw 51' so asto lock the latter in any desired position of adjustment. Also, as will be hereinafter set forth in more detail, the screw 51 may be employed for shifting the follower 45 out of engagement 4with the cam 26.

The `rear end portion of the rock-shaft 41 is provided with a radial crank 53 lixedto the shaft by means of a screwl 54, the end portion of which crank 53 is provided with a pin 55 which is pivotally connected with a link 56, the other 'end portionlof which is pivotally connected with a stub shaft 57 (see Fig. 3) carried by an oscillatory lever 58. A shoulder screw 59, threaded in a conventionalmanner within the end portion of the stub shaft 57, locks the link 56 in its proper relation with the oscillatory lever 58. The elements 44, 41 and 53 constitute a cam-follower lever, which when viewed in Fig. 1 is formed in the manner of a bell cranklever. p y

As may be `best seen in Fig. 3, the oscillatory lever S is formed upon one end of'a hollow shaft 60 which is rotatably mounted within an aperture 61 formed eccentrically within a cylindrical bearing member 62 which is locked within the lower portion of the bracket-arm 17 by means of a set screw 63. From this, it will be appreciated that rotary movements of the main shaft 21 will actuate the pattern cam 29 which, through the medium of the cam follower 45 and its associated shaft 41, will oscillate the lever 58 back and forth about the longitudinal axis of the hollow shaft 60.

Referring to Fig. 3, it is to be observed that the stub shaft 57 which connects the link 56 to the oscillatory lever 58 extends through the'lever 58 and is formed as an integral part of a guide member 64 which is carried by the lever 58. l

Referring now to Figs. 2, 3vand 4, the guide member 64 is provided lengthwise thereof with a straight-axis cylindrical guideway 65 which is disposed substantially lengthwise of the guide member 64 and of the lever Slidingly mounted within theguideway 65 is a apertured asat 67 to receive a hollow connecting element 68 secured to the tracking element 66 by means of a shoulder screw 69. The other end portion of the element 68 is pivotally received within an aperture formed in a member 70 and is secured to such meniber by way of a shoulder screw 71. From Figs. 1 and 4, it is to be appreciated that the member 70 is provided with an aperture 71' within which the rearward end portion of the'pitman 27 is received. A screw 72 is provided within the member 70 for locking the pitman 27 in its proper position.

Mounted between the cap portion of the shoulderA screw 71 and the member 70 (see Fig. 4) is the lower end portion of a link 73 whose upper end portion is pivotally secured by a cap screw 74 to the lower end portion of a crank-arm 75.` Figs. 1 and 2 illustrate the member 75 as being rigidly secured to a crank-shaft 76 which is rockably mounted between the opposite side walls of the bracket-arm 17 and in parallelism with the cam shaft 32 and the lower hollow shaft 60. The forward end portion of the shaft 76 extends through the forward wall of the bracket-arm 17 and has mounted thereon a finger member 77 which provides an operator with means for adjusting the shaft 76 about its longitudinal axis. An indicator plate, not herein shown, may be provided on the bracket-arm 17 adjacent the linger member 77 so as to show the operator the amount of adjustment imparted to the shaft 76.

From `the above, it is to be lappreciated that rotative adjustment of the shaft 76 will function through its crank-arm 75 and the link 73 to raise and lower the tracking element 66 within the guideway 65 to the end that the oscillations of the member lever 58 will irnpart greater or lesser endwise movements to the pitman 27. In this connection, it will be appreciated by viewing Fig. 3 that whenever the lower pivot axis of the link 73 Ais in coincidence with the longitudinal axis of the shaft 60 no endwise movements will be imparted f to the pitman 27 and, furthermore, as the lower pivot axis of the linkV 73 is moved upwardly along the length of the guideway 65 movements of increasing amplitude will be imparted to the pitman 27, assuming'that the amplitude of movement of the lever 58 remains constant, to the end that lateral zigzag movements will be imparted to the needle 27; Naturally, whenever the lower pivot axis of the link 73 is at the upper end portion of the guideway 65 the greatest amplitude of lateral zigzag movements will be imparted to the needle 24 for any given amplitude of movement of the lever 58. Thus the elements 73, 75, 76 `and 77 constitute means for altering the amplitude of lateral needle vibration.

In order to vary the neutral position of non-vibration of the needle 24 at the center or at either side of the field of lateral throw of the needle, whereby the needle may be caused to vibrate laterally from zero to maximum either across a center line through the field or entirely from either side of the eld of vibration of the needle, the

present mechanismis provided `with meanswhereby the guide member 64 may be adjusted relative to the oscillatory lever'58'. This means is in the form of a shaft 78 which is rotatably received within the hollow portion of the shaft60 and is thus disposed in a manner such that it is parallel with the rotary cam shaft 32. One end portion of the shaft 78 extends outside the contines of the bracket-arm 17 and is provided with a linger knob 79 whereby the operator may turn the shaft back and forth within the hollow shaft 60. The other end portion of the shaft 78I is lprovided with a pin 80 disposed eccentrically of the longitudinal axis of theshaft 78 and within an elongated slot 81 `provided within the rear face of the guidemember 64. ,From this it will be appreciated that as the shaft 78 is turned within its bearing, the pin 80 `will effectively swing the guide member 64 about the needle 24 to the end that zigzag movements will be produced at either side of the normal central position of the needle assuming that the contour of the pattern cam merely produces a constant back and forth movement of the lever 58.

Referring particularly to Fig. 4, it is to be observed that the guide member 64 is provided within an olset portion 81 provided with an aperture 82 within which is mounted a plunger 83 biased in one direction by means of a coil spring 84. Disposed opposite to the plunger 83 is a collar 85 xed upon the shaft 60 by means of a screw 86 and providing a recessed face designated by the numeral 87. As maybe best observed from Figs. l and 4, the face 87 has a central groove 88 into which the pointed end portion of the plunger 83 may be received so as to give the operator a tactual signal that the guide member 64 is in its neutral position relative to the oscillatory lever 58 and, thus, the needle will be in its normal central position whenever the lower pivot axis of the link 73 coincides with the axis of the rock shaft 60. The shoulder elements which define the face 87 act as side abutments which limit the swing of the guide member 64 in either direction away from its central position. By referring to Fig. 7, there is illustrated a pattern of zigzag stitches designated by the numeral 90, which pattern may be produced by the needle 24 whenever the guide member 64 is at its central position. Figs. 9 and 1l illustrate patterns of stitches 91 and 92v which may be respectively produced by the machine whenever the guideway 64 is thrown to one or the other side of its position of central adjustment.

From the above, it is to be understood that the present mechanism is characterized by having a rotary patternV cam which is adapted to impart lateral zigzag movements to the needle. This cam mechanism is designed in a manner such that various cams may be substituted for the purpose of providing different types of ornamental zigzag stitches. However, in addition to being cam actuated, the present sewing machine is provided with means in the form of handle 77 for altering the amplitude of lateral needle vibration and means in the form of handle 79 for varying the null or central point of the needle. In other words, various selective cams may be employed for imparting divers patterns of lateral motion to the needle but at the same time the amplitude of this motion, as Well as the central position of the needle, may be varied` by movement of the finger knobs 77 and 79. Furthermore, due to the presence rof the arm 50 with its abutment screw 51', the pattern cam 29 may be removed from the machine and thereafter the' machinek may be operated in a manner of a straight stitching machine. In this connection, it will be appreciated that the spring 46-wi11 maintain the arm 50 against the abutment screw 51 in a predetermined position so that the machine may be operated either as a conventional straight stitching machine or as a zigzag machine which may produce various patterns of stitches depending entirely upon the manual operation of the nger knobs 77 `and 79. Also, if desired, the cam 29 may be left on the machine and the operator by advancing the screw 51 downwardly into engagement with the arm 50 can lift the follower 45 clear of the cam so as effectively to throw the cam out of operation.

As mentioned hereinabove, Figs. 5 to l2 inclusive illustrate a modified form of the present invention. In this form. of the invention, the. guide member 64 has been replaced by a different guide member 93 and the member 70 of the pitman 27 is replacedv by a new member 94 but in all other respects. the second. form of the invention is the same as that described hereinabove. It is the purpose of themodied form of guide member 93 to insure that the amount of vibration or zigzag movements of the needle produced by the rotary pattern cam 24 will be formed about a common center line irrespective of the:

5 and 6, the guide member- 93 is provided with a straightaxis cylindrical guideway 65 which is tracked by the same tracking element 66 as was provided in connection with the first form of the invention. However, it will be observed from Fig. 6 that the central shoulder portion 95 of the tracking member is Slidingly mounted within a slot 96 which is provided in the member 94 and elongated in a direction lengthwise of the latter member so as to provide in leffect a lost motion connection between this member and the tracking means.

Also formedin the guide member 93 is a curved-axis guideway 97 which is disposed lengthwise of the member 93 and about an arc drawn with the pivot 28 of the pitman 27 as its center when the guide member 93 and its associatedv lever 58 are disposed centrally of their total swing pattern. The radius of this arc is designated in Fig. 7 by the letter R. Slidingly disposed within the curved guideway 97 is a cylindrical tracking element 98 which is carried directly by the member 94. From this, it will be appreciated that as the member 94 and its associated pitman 27 are swung up and down by way of the mechanism including the link 73 the element 98 will track the curve 97 to the end that the pitman 27 will be swung about its pivot 28 and such swinging movements of the pitman 27 will not impart any lateral movements to the needle-bar gate 25 whenever the oscillatory lever S8 and the guide member 64 are disposed centrally of their total swing pattern. Thus, this structure prevents, as the amount of vibration of the lever 64 is increased or decreased, `all of the stitches from being made on anything but a common center line such as represented by line 99 of Fig. 7. In all other respects, however, the second form of the present invention, as is particularly illustrated in Figs. 5 and 6, is the same as and functions in a manner similar to the first form of the invention which is illustratedin Figs. 1 to 4,

inclusive.

It is manifest that. changes may be made in the form and construction of the present invention without departing from the material principles thereof. It is not therefore desired to confine the invention to the exact forms herein shown and described, but it is desired to include all forms which properly come within the purview of the appended claims:

Having thus set forth the nature of the invention, what I claim herein is:

l. In an ornamental seam sewing machine, a hollow bracket-arm, a rotary main drive shaft disposed lengthwise of and within said bracket-arm, a vibratory needlebar frame carried by said bracket-arm, a needle-bar journaled for endwise reciprocation in said frame, a rotary pattern cam, and means associated with said pattern cam for vibrating and controlling the vibrations of said frame, said means comprising four parallel shafts mounted within and crosswise of said bracket-arm, one of said shafts being connected with said main shaft for rotation thereby and having said rotary pattern cam removably mounted thereupon, a lever disposed within said bracket-arm and pivotally supported at one end thereof by a second one of said parallel shafts, a cam follower lever pivotally supported by a third one of said shafts and being biased against said rotary pattern cam, a link connecting said cam follower lever with the free end portion of said first mentioned lever for rocking the latter about its pivot, a pitman having one end connected with said needle-bar frame and its other end connected with said first mentioned lever for transferring the motion of such lever to the needle-bar frame, and means carried by the fourth of said shafts and connected with said pitman for adjusting the connection point of said pitman and its associated lever lengthwise of such llever thereby to alter the amplitude of needle-bar frame vibration.

2. In an ornamental seam sewing machine, a. hollow bracket-arm, a rotary main drive shaft disposed lengthwise of and within said bracket-arm, a vi'bratory needle-bar frame carried by said bracket-arm, a needle-bar journaled 7l for endwise reciprocation in said frame, a rotary pattern cam, and means associated with said pattern cam for vibrating and controlling the vibrations of said frame, said means comprising, four parallel shafts mounted `within and crosswise of said bracket-arm, one of said shafts being connected with said main shaft for rotation thereby and having one of its ends extending through a side wall of said bracket-arm with said rotary pattern cam being removably mounted upon the distal end thereof, a lever disposed within said bracket-ann and pivotally supported at one end thereof by a second one of said parallel shafts, a cam follower lever pivotally supported by a third one of said shafts and being biased against said rotary pattern cam, a link connecting said cam follower lever with the free end portion of said tirst mentioned lever for rocking the latter about its pivot, a pitman having one end connected with said needle-bar frame and its other end connected with said tirst mentioned lever for transferring the motion of such lever to the needle-bar frame, the fourth of said shafts having one of its ends extending through the same bracket-arm sidewall as said tirst shaft and supporting on its distal end a hand lever for turning such shaft, and means carried by the fourth shaft and connected with said pitman for adjusting the connection point of said pitman and its associated lever lengthwise of such lever thereby to alter the amplitude of needle-bar frame vibration.

3. In an ornamental seam sewing machine, a hollow bracket-arm, a rotary main drive shaft disposed lengthwise of and within said ybracket-arm, a vibratory needlebar frame carried by said bracket-arm, a needle-bar journaled for endwise reciprocation in said frame, a rotary pattern cam, and means associated with said pattern cam for vibrating and controlling the vibrations of said frame, said means comprising, four parallel shafts mounted within and crosswise of said bracket-arm, one of said shafts being connected with said main shaft for rotation thereby and having one of its endsk extending through a side wall of said bracket-arm with said rotarypattern cam being removably mounted upon the distal end thereof, a lever disposed within said bracket-arm and pivotally supported at one end thereof `by a second one of said parallel shafts, a guide pivotally mounted upon the free end portion of said lever for movement transverse of the lever axis, a cam follower lever pivotally supported by a third one of said shafts and being biased against said rotary pattern cam, a link connecting said cam follower lever with the free end portion ofsaid first mentioned lever for rocking the latterabout its pivot, a pitman having one end connected with said needle-bar frame and its other end connected with said guide for transferring the motions of such guide to the needle-bar frame, the fourth of said shafts having one of its ends extending through the same bracket-arm side wall as said first shaft and supporting on its distal end a hand lever `for turning such shaft, means carried by the fourth shaft and connected with said pitman for adjusting the connection peint of said pitman and said guide lengthwise of such guide thereby to alter the amplitude of needle-bar frame vibration, means extending lengthwise and coaxially of said second shaft for adjusting said guide rabout: its pivot axis and relative to said tirst mentioned lever thereby to alter the neutral position of said needle-'bar frame, and a hand lever disposed at the same side of said bracket-arm as the pattern cam for actuating said last mentioned means.

4. In an ornamental seam sewing machine, a vibratory needle-bar frame, a needle-bar journaled for endwise reciprocation in said frame, and connections for vibrating said frame; said last-mentioned connections comprising, an oscillatory lever pivoted at its one end about a fixed axis, a pitman having one end operatively connected with said frame by way of a pivot, and means operatively connecting the other endV of said pitman with .said lever for transferring the motions of the lever to said frame; said last mentioned means including a straight-axis guideway and a curved-axis guideway carried by said lever with each guideway disposed substantially'lengthwise of said lever, a first tracking element slidably disposed lengthwise of and within said curved guideway and connected with said pitman thereby to shift the latter lengthwise of itself in response to movement of said lever about its fixed axis, a second tracking element slidably disposed lengthwise of and within said straight-axis guideway and connected with its associated guideway and pitman whereby said pitman willbe prevented from moving laterally of such guideway, and means for adjusting said pitman lengthwise of said guideways.

5. In an ornamental seam sewing machine, a vibratory needle-bar frame, a needle-bar journaled for endwise reciprocation in said frame, and connections for vibrating said frame; said last-mentioned connections comprising, an oscillatory lever pivoted at its one end about a fixed axis, a pitman having one end operatively connected with said frame by way of a pivot, .a curved-axis guideway carried by said lever with its axis being formed as an arc of a circle drawn about the pitman pivot when said guideway is disposed centrally of its swing pattern, a tracking L lneedle-bar frame, a needle-bar journaled for endwise reciprocation in said frame, .and connections for vibrating `said frame; said last-mentioned connections comprising an oscillatorylever pivoted at its one end about a fixed axis, a pitman having one` end operatively connected with said frame by way of a pivot and its other end formed with an elongated slot, va curved-axis guideway carried by said lever with its axis being `formed as an arc of a circle ldrawn about the pitman pivot when said guideway is Vdisposed centrally of its swingV pattern, a tracking element carried by the otherend portion of said pitman and extending into said curved guideway, means for adjusting said pitman lengthwise of said lever, and means prei mounted within said cylindrical guideway, a pin extending transversely from vsaid cylindrical tracking element and through the slot formed in said pitman, and means carried by said pin and slidingly embracing the opposite sides of said pitman.

France Aug. 28, 1950 

